Improvement in excavators



y taluni' Sitte' eine erta.

THOMAS SYMONDS, OF PORTLAND, MAINE, ASSIGNOR `TO `JOHN B. CURTIS,

OF SAME PLAOF.

f Letters latent No. 111,787, dated February 14, 18'21.

IMPROVEMENT IN EXCAVATORS.

The Schedule referred to' in these Letters Patent and making parl: of the same.

To all whom. it may concer-n .f

Be it known that I, THOMAS SYMoNDs, of. the city of Portland, in the county of Cumberland and State of Maine, have invented a new and useful Improved Excavator; and I-do hereby declare the following to be afull, clear, and exact description thereof,

vreference being had to the accompanying drawing, in

Figure l is a side elevation of my improved `excavator with the bucketshut; f

Figure 2 is a side view of the bucket when the shaft or beam is not vertical;

Figure 3 shows the excavator'. when the bucket is open; 'and A Figure 4 is a front view of same. i A

My invention relates to an improved method of opening and shutting the bucketsof dredging-machiues'. i

By the method now in use the buckets are opened and shut by 'means of levers connected with the edges of the buckets and a slide moving up and down on the beams or poles by which the buckets are lowered or raised. It is evident that by thismethod there must be a loss of power and no largeamount of leverage, v

My method is illustrated iu figs. 1, 3, and 4 of the drawing. -V

F F show the buckets, which are of the usual form, and are connectedwith, the vflame E in the usual manner.

The frame E E, holding thc buckets and the shaft H, is connectedwith one beamor pole Q, instead of with two, as is usual.

Connected with the edges ofthe buckets F F are the two levers B B, each of which is pivoted at R to an arm, A.

The other end of the arm A is pivoted lto the beam or pole at D. The pivot R has also the pulley O between the bifurcation of 'the arm A.

At vthe center of the arms A A are attached the ropes or chains operating the buckets and shutting the same. Each of these ropes passes under and over the pulley opposite the arm to which it isat-J tached, and then in the same direction around the shaft H, to which they are also attached.

Connected with the buckets at L are the ropes which open the buckets, and which are attached to the shaft H and pass around itiu a directionopposite to that in which the ropes connected with levers A A pass aroundit.

The shaft H is rotated by the ropes S and T, one giving it a rotation in one direction, the other rotating it iu-the other direction.

The great superiorityV of my arrangement and coustruction'is obvious inthe greater amount of leverage obtained, and in the power saved.

The arms A and B form a toggle-joint, the power of which is well known, and it must be evident that the more nearly shut the bucket-s F F are, the greater the force-applied to shut them by means of thetoggle formed by thearms mentioned.

I do not claim suoli a device as that described and claimed in patent No. 73,678, granted to Thomas and Augustin Walsh, January 21, 1868. The di'erence between this device and mine is- First, in the manner in which the arms or levels closing buckets are attached to the same.

Second, in the arrangement'of the chains by means of which power is applied to said levers.

' What I claim as my invention, and desire to secure by Letters Patent of the United States, is y The combination of the buckets F F, of the arms A A and B B, applied -as described, the handle Q, the shaft H, and the ropes, arranged as set forth.

THOMAS SYMONDS Witnesses:

Winnmm B. CLIFFORD, GEORGE E. BIRD. 

